Timer escapement



Nov.25, 1947. v c. E. GODLEY I 2,431,355

DIMER ESCAPEMENT Filed Nov. 24, 1941 GSheets-Sheet 1 INVENTOR 674,225 IBY j X ATTORN Nov. 25, 1947. c. E. GODLEY 1 2,431,395

TIMER ESCAPEMENT Filed Nov. 24, 1941 6 Sheets-Sheet 2 U I mun INVENTOR(Jar/2: .ZT a/Zqy a flm ATTOR Nov. 25, 1947.

C. E. GODL'EY TIMER ESCAPEMENT Filed Nov. 24, 1941 6 Sheets-Sheet I5INVENTOR jar/4s Z. J/qy.

ATTORN Nov. 25, 1947. c. E. GODLEY 2,431,395

TIMER ESCAPEMENT Filed Nov. 24, 1941 v e Sheets-Sheet 4 v ATTORNE NOV.25, 1947. c, GODLEY 2,431,395

TIMER ESCAPEMENT Filed Nov. 24, 1941 6 Sheets-Sheet 5 INVENTOR E E'}drZa6 zrgddleg,

ATT NEY Nov. 25, 1947.

Filed Nov. 24', l94l EBB-55' TIMER GODLEY 2,431,395

ESCAPEMENT 6 Sheets-Sheet 6 INVENTOR ATTO Y5.

Patented Nov. 25, 1947 TIMER ESCAPEMEN T Charles E. Godley, Ferndale,Mich., assignor to King-Seeley Corporation, Ann Arbor, Mich., a

corporation of Michigan Application November 24, 1941, Serial No.420,288

15 Claims. 1

The present invention relates to timing devices, and in particular isdirected to the provision of an improved timer for producing an audibleor other signal, or other operation, at the expiration of a selectivelyadjustable interval; and this application is a continuation in part ofapplicants copending application, Serial No. 379,925, filed February 21,1941.

The principal objects of the present invention are to provide a timer ofthe above generally indicated character, embodying an improved clockmovement which is economical of manufacture and assembly, and which ispositive and reliable in operation; to provide such a timer embodying animproved positive escapement, employing a pallet adapted in one rotativeposition to lock the escapement wheel and adapted in another rotativeposition to permit the escapement wheel to advance; to provide such astructure, wherein the pallet is withdrawn from locking position bymeans of an extension spring, which is readily adjustable to alter thetiming of the escapement and wherein the pallet is urged into lockingposition by the advance of the escapement wheel; and to generallyimprove the construction and arrangement of timing devices of the typeto which the present invention relates.

With the above as well as other objects in View, which appear in thefollowing description and in the appended claims, preferred butillustrative embodiments of the invention are shown in the accompanyingdrawings throughout the several views of which corresponding referencecharacters are used to designate corresponding parts and in which:

Figure 1 is a view in front elevation of a timer embodying theinvention;

Fig. 2 is a view in axial vertical section through the timer of Fig. 1;

Fig. 3 is a detail view, taken along the line 33 of Fig. 2;

Fig. 4 is a fragmentary sectional View, taken along the line 44 of Fig.2;

Fig. 5 is a detail view, taken along the line 55 of Fig. 2;

Fig. 6 is a detail view in section, taken along the line 6-6 of Fig. 5;

Fig. 7 is a view in section taken along the line 'l-'! of Fig. 5;

Fig. 8 is a View in section taken along the line 8--8 of Fig. 2;

Fig. 9 is a view corresponding generally to Fig. 8, but showing thehammer cocking mechanism in the off or released position;

Fig. 10 is a, view taken along the line Ill-l0 of Fig. 9;

Fig. 11 is a fragmentary detail view, taken along the line H--ll of Fig.8;

Fig. 12 is a fragmentary detail view, taken along the line [2-42 of Fig.9;

Fig. 13 is a fragmentary detail view, taken along the line i3i3 of Fig-9;

Fig. 14 is a fragmentary detail view, taken along the line i il4 of Fig.9;

Fig. 15 is a fragmentary detail view, taken along the line Iii-l5 ofFig. 10;

Fig. 16 is a diagrammatic View of the improved escapement, based uponFig. 5, but drawn on an enlarged scale;

Fig. 17 is a View corresponding to Fig. 16, but showin the elements ofescapement in difierent relative positions;

Fig. 18 is a view corresponding generally to Fig. 5, but showing theadaptability of the present escapement to wheels of different numbers ofteeth;

Fig. 19 is a view in front elevation of a modified dial construction;

Fig. 20 is a View in elevation of a modified construction of an escapewheel;

Fig. 21 is a view taken at right angles to Fig. 20;

Fig 22 is a plan View of a fixture for assembling the hereinafterdescribed clutch connection;

Fig. 23 is a, view in vertical central section, taken along the line23-23 of Fig. 22;

Figs. 24, 25 and 26 are comparative views of a modified escapementconstruction;

Fig. 27 is a view similar to Fig. 24, showing a further modification ofthe escapement mechanism;

Fig. 28 is a side elevation of the balance staff and escapement elementemployed in Fig. 2'7; and

Fig. 29 is a view illustrating the manner in which the escapementelement of Figs. 2'? and 23 is formed.

It Will be appreciated from a complete under standing of the presentinvention that the ire-- provements thereof may be embodied in timingmechanism of widely varying specific construetions, and intended for arelatively wide variety of difierent purposes. Also, in a generic sense,the character of the signal produced by the device may be of eitheraudible, visual, or other character. In an illustrative but not in alimiting sense, the present improvements are herein dis-- closed inconnection with a timing unitwhich operates to provide an audiblesignal.

Referring more particularly to Figs. 1 and 2 of the drawings, thepresent mechanism comprises generally a hammer mechanism designated as awhole as 35, which is directly connected to a main arbor 32, which, inturn, is adapted to be rotated in a starting direction from a normal orstarting direction by means of a setting dial 34 and which is driven inthe opposite or'timing direction by a movement designated as a whole asas. It will be appreciated that the movement 36, which has a clutchconnection with the arbor so, is effective, upon release of the dial 34,to drive the hammer mechanism in the return direction at a substantiallyuniform rate, and that, consequently, the time interval for which thedevice is set is determined by the degree of angular movement throughwhich the arbor 32 and the hammer mechanism 38 are moved in the settingdirection by the dial 3%. As is described in more detail hereinafter,the setting movement of the dial also serves to wind or load the mainspring 38, associated with the movement 36, and the initial settingmovement also acts to cock the hammer mechanism 53. The hammer mechanismhas associated therewith means to trip the same at the conclusion of thereturn movement, which tripping action enables the hammer mechanism toeffect an operation. As previously mentioned, the hammer may, in ageneric sense, be caused to effect a wide variety of operations andconsequently, throughout the present description and in the claims,except where a specific type of operation is particularly referred to,the term hammer mechanism is used in a generic sense, as referring to asuitable operator or like part. In the present instance, the hammermechanism is arranged to ring a bell, and as illustrated, the hammermechanism is of the multiple type, and produces a succession of bellnotes.

Considering the above-mentioned elements in more detail, and referringparticularly to Figs. 2, 5 and 7, the movement 35 comprises a main gear49, which drives the arbor 32 at a rate determined by the escapement.The escapement comprises the escapement wheel 52, a pallet Ml, a balancewheel 65, and an adjustable pallet spring 58.

More specifically, the main gear is rotatably journalled on a portion 58formed on the arbor 32, and a face plate 52 secured to the back of themain gear 40 abuts a shoulder formed on the arbor, thereby preventingmovement of the ear G8 to the right relative to the arbor 32. The otherface of the main gear 55 is provided with a face plate 56, which is alsoseated on the portion 55 and directly and frictionally engaged by aclutch plate 53. The plate 58 is rigidly secured to and directlyrotatable with the arbor 32.

A feature of the present invention resides in the method of andarrangement for securing the clutch plate 58 to the arbor 32 and foraccurately predetermining the pressure which the plate 53 exerts againstthe main gear as, thereby, of course, determining the torque which theclutch can sustain without slippage. As clearly appears in Figs. 2 and23, the inner marginal edge 55 of the clutch plate 53 seats against arelatively short fiat portion 62 on the arbor 32, and, preferably, therighthand face of the clutch plate 5 3, immediately adjacent the centralopening therein, lies slightly spaced from a shoulder 55 on the arbor32. In accordance with the present invention, the central opening in thclutch plate 58 is given a slightly rough or toothed marginal surface,and also, prior to assembly thereof with the arbor 32 and the gear 55,the central portion of the clutch plate 58 is pressed from the main bodyof the plate. In assembly, after the main gear 55 is applied to thearbor 82, the clutch plate 58 is simply pressed thereon, and, it beingunderstood that the opening in the clutch plate 58 is of a diameter veryslightly less than the diameter of the portion 52 of the arbor, thepressing on of the clutch plate 53 causes the central opening therein tosolidly bind upon the portion 52 with a ratchet action, which positivelyprevents removal thereof. The pressing on movement of the plate 55ultimately brings the main body portion thereof into frictionalengagement with the face plate 55. The clutch plate 53 is preferablyslightly cupped, with the concave face thereof presented to the faceplate 55, and is also preferably provided with a series of equiangularlyspaced, radially extending notches 59, four being preferable. Ihesenotches extend inwardly from the periphery of the plate 58 and theirlength is preferably between 50% and of the radius of the plate 58. Theplate 58 is preferably formed of springlilre material, and consequently,in the assembled position Of the parts, a substantial proportion of theoriginally concave facial area of the plate 58 resiliently engages theface plate 55 with a frictional holding effect which progressivelyincreases as the pressing on movement of the clutch plate 58 iscontinued.

It will be understood, as hereinafter described, that even in the normalor zero setting of the timer, the main spring 38 is.loaded to asubstantial extent, and this loading is, of course, increased each timethe dial is rotated to set the timer for a predetermined timinginterval. The holding effect of the clutch connection between themembers 58 and 58 must, of course, be sufficient to reliably sustain themaximum loading of the spring 38 without introducing slippage. On theother hand, in order to facilitate a winding operation, and also tominimize the duty of the clutch elements, it is desirable to maintainthe slippage value of the clutch at as low a value as is consistent withthe just-mentioned duty. These considerations make it desirable toaccurately gauge the frictional holding effect of the clutch elements,and in accordance with the present invention, this may be accomplishedas an incident to the above-mentioned pressing on operation.

Referring particularly to Figs, 22 and 23, an illustrative fixturecomprises a die 5|, having a pocket 53 therein, in which the clutchplate 58 may be seated, the form of the pocket being such that only theradially central parts of the plate 53 are engaged thereby. With plate58 thus preliminarily positioned within the pocket 53, the arbor 32,with the plates 52 and 56 and the gear 40, previously assembled thereon,may be projected downwardly through the opening in the die 5| towardsthe position of the parts shown in Fig. 23. The latter projectingmovement brings the gear 40 into relatively non-rotative engagement witha spring loaded indicating member 55. Preferably and as illustrated,this relatively non-rotative connection is afforded by forming the innerperipheral face of the member 55 as an internal gear with which the gear40 may mesh. The assembly 55 is provided at one side with a pointer 51,which is adapted to register with a relatively fixed scale 6|, and isalso provided with a diametrically opposite extension 63 to which oneend of the loading spring 55 is secured. The other end of the spring65.is anchored. It will be understood that any suitable means (notshown) may be employed to rotatively support the assembly 55 above thedie 5|, the principal requirement being that the toothed portion of theassembly 55 shall be of sufficient depth so that the gear 40 remainsmeshed there with throughout the full range of the pressing on movementof the clutch plate 58.

With the parts thus preliminarily positioned, a compressive force may beapplied between the upper end of the arbor 32 (Fig. 23) and the die 5|,which forces portion 62 on the arbor 32 through the roughened centralopening in the plate 58. Concurrently with the application of thispressing force, a rotative force may be applied to the arbor 32, so asto cause the same to rotate in a clockwise direction, as viewed in Fig.22. The initial pressing on movement of the plate 58 affords anon-rotative connection between the plate 58 and the arbor 32.Consequently, this rotation of the arbor 32 drives the clutch plate 58.As soon as the pressing on movement is continued far enough to bring theclutch plate 58 into engagement with the face plate 56, a rotative forceis applied through the clutch to the gear 39. .This force tends torotate the assembly 55 in a clockwise direction, as viewed in Fig. 22,which latter rotation stresses the spring 65. It will be evident thatthe degree to which the spring 65 is stressed, and, consequently, thescale reading to which the pointer 5'! is moved, depends upon thefrictional holding efiect between the plates 56 and 58, and that thisholding effect is progressively increased as the pressing on movement iscontinued. The assembly.operation is, of course, completed when thepressing on movement brings the pointer 51 to the desired scale reading.

The main gear 4i drives the escapement through a train of intermediategears comprising the pinions iii and 72 and the gears 14 and 15 whichare carried by a stafl 18, and further comprising the pinions 89 and 82and the gear M, which are carried by the staff 86. The staff 85 alsocarries the escape wheel 42. The staffs l3 and 86, and the staff" 98which carries the balance wheel 46 and the pallet 4d, are supported byfront and rear movement plates 92 and EM, which, in turn, are rigidlymaintained in predetermined spaced relation to each other by thehereinafter described pillars 96. As illustrated, the staffs l3 and 86are each provided with reduced end portions, which are freely rotatablewithin corresponding bearing openings provided therefor in the movementplates 92 and M, it being understood that the staffs are permitted tohave a very slight amount of longitudinal play so as to insure a freerunning condition thereof. The opposite ends of the staff 9d arepointed, one such pointed end being received in a corresponding taperedseat formed in a plug 98 which is conventionally pressed through themovement plate 92. lhe other tapered end of the staff 93 is received ina corresponding tapered seat formed in a plug see, which, in thepreferred practice of the invention, is relatively freely slidablewithin the opening 532 provided therefor in the movement plate ed. Aleaf spring HM, one end whereof is riveted to the movement-plate 94 asby a rivet E05, has its other end [93 bearing directly upon the back ofthe plug Mid, and acts to continuously urge the same towards the plug98, thereby maintaining a predetermined loading between the staff so andits bearing. A limit to such inward movement is afforded by the shoulderHt on the plug Hit, and a limit to outward movement of the plug we isafforded by a member H2, carried by the hereinafter described hammermechanism. It will be understood that the staffs 78 and 85 may beprovided with bearings which correspond to those described for the staff90, it being appreciated, however, that the latter type bearings are ofprincipal importance in connection with the staff 953, since this staffis driven in one direction by the escapement spring 48, and consequentlyis considerably more sensitive to changes in bearing pressures than arethe other staffs which are driven entirely by the relatively heavy mainspring 38. It is found in practice that certain of the assemblyoperations, which occur after the main and intermediate gears and theescapement elements are assembled between the movement plates 9E3 and92, tend to distort the plates, and any binding and locking of the staff90 which might otherwise be caused by such deformation is entirelyovercome by the just-described free running bearings for the staffmentioned.

It will be appreciated that in usual constructions, a substantial partof the ticking noise produced by the operation of the escapement is dueto the play which normally must be allowed between the balance staff andits bearings, which play enables the balance staff to oscillate in anaxial direction. Constructions heretofore used have employed, of course,an adjustable bearing arrangement. The setting of the adjustable bearingis, however, a rather critical operation and one that complicates theassembly operation. Moreover, at least some play must be left in thebearing, as will be understood, to accommodate changes in temperatureand the like. The present arrangement not only eliminates these assemblydifficulties, but also entirely eliminates the necessity for any play inthe balance staff bearings, since the spring ltd serves to continuouslyhold both ends of the staff seated in the corresponding bearings. Theelimination of this play in the bearings materially reduces theintensity of the ticking noise, particularly when the present bearingarrangement is employed in connection with a flexible escape wheel ofthe type shown in Figs. 20 and 21 and described hereinafter.

The movement plates t2 and 525 are also provided with aligned bearingopenings in which the arbor 32 is journalled, it being noted that axialplay of the arbor 32 is limited by the engagement of the shoulder 9ithereon with the movement plate 9 1 and by the engagement of theshoulder 93 thereon with the movement plate 92.

The pinion it, which directly meshes with the main gear til, and thecompanion gear M are rigid with respect to each other and are ressfitted upon the corresponding shaft it. The immediately adjacent pinionl2 and its gear iii in turn are rigid with each other and are freelyjournalled on the staff 78 between the just mentioned gear i l and asleeve 1 M, which, in turn, is press fitted upon the staff 18.Similarly, the pinion 80 and the gear 84 are rigid with respect to eachother and are press fitted upon the staff 36. The pinion 82 and theescapement wheel :52, in turn, are rigid with each other, and are freelyjournalled on the staff 86 between the gear 84 and a sleeve i i t, whichis press fitted on the staif 86.

It will be noted that each of the staffs l8 and 85 carry two gear andpinion assemblies, which pyramiding 0r doubling up of the gear andpinion assemblies is advantageous for several reasons. First, thispyramiding obviously reduces the required number of staffs, and thus notonly simplifies the unit as a whole but reduces the space requirementsthereof. Further, and of perhaps even greater importance, thispyramiding enables the load reactions on the staffs to be balanced outin such a way as to avoid any heretofore encountered binding of thestaifs as the gears and pinions wear in.

Considering now the escapement mechanism, and referring particularly toFigs. 5, 6, 7, 16 and 17, the previously mentioned balance wheel 46, thepallet 44, and a spring hook E29 are press fitted upon the staff and sorotate as a unit 7 therewith. The pallet 44 is formed to define a tooth522 and a locking shoulder I24. The looking shoulder I2 3 co-operateswith each tooth of the escape wheel to momentarily stop rotation of thelatter when the parts occupy the relative positions shown in Fig. 16,and the tooth I22 of the pallet is engaged by each successive tooth ofthe escape wheel 42, upon release of such tooth from the shoulderii-lfi, so as to rotate the pallet 44 from the position shown in Fig. 17back to the blocking position shown in Fig. 16. The pallet 44 is rotatedfrom the blocking position of Fig. 16 in a clockwise directionsurhciently far to release the escape wheel tooth from the shoulder I24,by

means of the extension spring 58, one end where- 1 of is hooked to thespring hook I20, and the other end whereof is secured to a bracket I26.The other end 01' the bracket i126 rides in a guide slot l28 formed inthe bracket support I39, which support is rigichy secured to theadjacent movement plate 92. The bracket I26 also receives a threadedadjusting screw I32, which may be rotated in one direction to extend thespring 48. Rotation of the screw in the opposite direction enablescompression spring iSi to force the bracket i213 to the right, therebyshortening the spring 63. The use of an extension type spring forco-operating with the pallet 34 is regarded as a feature oi the presentconstruction, since such extension spring can very readily be adjustedafter all or" the parts are assembled, so as to vary the tension of thespring 48 throughout a very considerable range.

The parts are shown in Figure in the position to which the pallet 45 ismoved by the passage therepast of a tooth of the escape wheel 32. Whenthe pallet t4 occupies the just mentioned position, the pilot spring 18occupies an over center position in which it urges the pallet 34 aclockwise direction, as viewed in Figures 5, l6 and 17. As long,however, as the pallet occupies the just mentioned position, it blocksthe tooth b of the escape wheel 42 and holds the latter againstrotation. The spring do is efiective to move the pallet 43 from the justmentioned position toward the position shown in Fig. 1'7, during thecourse of which movement the shoulder E thereof passes out or blockingrelation to the tooth b of the escape wheel 42, enabling the latter tostart in a clockwise direction under the influence of the main spring38, which, as described below, acts directly against the arbor 32, whicharbor is clutched to the escape wheel 42 through the previouslymentioned main gear so and the intermediate gears. As soon as the escapewheel is free of the shoulder I24, the tooth 1) thereof moves toward thetooth I22 oi the pallet to, which latter tooth is now in the path ofmovement of the tooth b. Consequently, the tooth b or". the escape wheelstrikes the tooth of the pallet l and rocks the latter from the pc .511or l? to the position of Fig. 16, during which movement the palletspring ts is again loaded. This movement of pallet dd brings theshoulder iZt into blocking relation to the next successive tooth of theescape wheel 42, enabling the pallet to momentarily stop the movement ofthe escape wheel. As soon, however, as the pallet spring 43 is enabledto overcome the rotative force imparted to the pallet i l by the escapewheel this spring again rocks the pallet out of the blocking position ofFig. 16 towards the free position of Fig. 17.

An important feature of the pallet 44, as illustrated in Figs. 16 and1'7, is the rounded corner I25 between the braking shoulder I24 and thenotch 52? in advance of the tooth PM. It will be noted from Fig. 16 thatthe point on shoulder i2 1 engaged by the spoke of the escape wheel 42is in an area which is cylindrical in form, but that a limited clockwisemovement of the pallet it under the influence of spring 48 shifts thepoint oi engagement to the rounded corner I25.

As the point of engagement moves over the rounded corner I25, thedistance of the point of engagement from the center of stafi 98progressively decreases. This progressive decrease of the radius of thepoint of engagement has two important functions: first, it reduces theeffect of the frictional resistance to clockwise rotation of pallet stto compensate for the progressive reduction in the force exerted byspring 48 and, second, it permits the escape wheel to begin its movementand accelerate before it is actually released by pallet A l, thusincreasing the speed with which it strikes tooth I22.

It will be appreciated that the spring 48, balance wheel 66, pallet hookiii and stafi constitute an escapement system, which oscillates betweenthe blocking and free positions shown in Figures l6 and 17,respectively. It will further be appreciated that the escape wheel 42 isenabled to advance one tooth during the course of one full cycle ofmovement of the just mentioned escapement system. The amplitude of themovement may be expected to vary somewhat in accordance with the loadingof the main spring and in accordance with the angular spacing betweensuccessive teeth of the escape wheel The period or rate of the movement,however, is determined substantially entirely by the weight of themoving parts and by the tension of the spring 43, so that for any giventension of the spring 43, such rate or period is substantiallyindependent of the loading of the main spring and also is substantiallyindependent of the angular spacing between the teeth of the escape wheel42.

As afore-mentioned, the period or rate of the escapement can be variedover a substantial rang by varying the tension of the spring 48,variations up to 30% having been found readily available in practice. Itis preferred in practice, therefore, to employ the adjustment of thetension of the spring 48 as the means for calibrating the timer, anincrease in tension serving to increase the escapement rate and adecrease in tension serving to decrease the escapement rate. Thisadjustment can, of course, be made by the simple expedient of turningthe mounting screw I32 in one direction or the other.

As was previously mentioned, the escape rate appears to be substantiallyindependent of the angular spacing between the successive teeth of theescape wheel 42. Consequently, by altering the number of teeth on theescape wheel, an

exceedingly wide variation in the escape rate is readily available. Morespecifically, the escape wheel shown in Fig. 5 is provided with eightteeth, whereas the wheel of Fig. 18 is provided with four teeth.Accordingly, the wheel of Fig. 5 requires twice as long to make acomplete revolution as does the wheel of Fig. 18, and the structure ofFig. 5 has one-half the escape rate of the structure of Fig. 18. It willbe understood, of course, that by employing twice the number of teeth asare employed in the wheel of Fig. 5, the escapement rate is reduced byone-half, and that other proportionate increases and decreases of theescape rate provided by the structure of Fig. are obtainable bycorresponding other proportionate decreases and increases in the numberof teeth on the escapement wheel.

The actual escape rates employed and the gear ratio between the escapewheel and the arbor 32 determine, of course, the time interval affordedfor each full 360 of movement of the arbor 32 and the dial l, or foreach fraction of such full movement. Various escape rates and gearratios may be employed, as will be understood. By way of illustrationbut not of limitation, it is preferred to adjust the escapement so as toprovide an escape rate of 216 escape teeth per minute, whichcorresponds, of course, with an eighttoothed wheel, to 2'7 escape wheelrevolutions per minute and, with a four-toothed wheel, to 54 escapewheel revolutions per minute. It is further preferred to adjust the gearratio between the escape wheel so that the eight-toothed wheel providesa sixty minute period for a full revolution of the dial. With this gearratio, a four-toothed wheel, of course, provides a 30 minute timinginterval and a sixteen-toothed wheel provides a two hour timinginterval.

As previously mentioned, the movement plates 92 and 9d are maintained infixed, spaced relation to each other by means of pillars 96, three ofwhich are shown in the drawings and which are equiangularly spaced. Afeature of the present construction resides in forming a positive butreadily releasable connection between the pillars 93 and the plates 82and 53 5-. Referring particularly to Fig. 15, each movement plate isprovided with a keyhole slot $9 individual to each pillar, and eachpillar 96 is notched, as indicated at 8'5, to define fiat-sided sections85 which are narrow enough to pass through the neck of the correspondingkeyhole slot. It will be understood that a pillar is assembled withrespect to its plates and 94 by rotating the pillar so as to bring thenarrow portions 95 thereof into alignment with the necks of the keyholeslots, and that after the pillar is moved into the bases of the keyholeslots. the same is rotated through a slight angle so as to bring thenarrow portions 95 out of alignment with the necks of the slots. The fitbetween the slotted pillars and the slots in the movement plates ispreferably such as to frictionally prevent unintentional rotation of thepillars. It will further be appreciated that the notches er in thepillars 95 are spaced along the bodies thereof in accordance with thedesired spacing between the movement plates 92 and lit, and that thelength of each such notch is substantially equal to the thickness of theassociated movement plate.

Referring particularly again to Figs. 2 and l, the main spring 38 is ofusual spiral form, one outwardly turned end E li! whereof is hookedthrough an opening provided therefor in the main spring housing Hi2, andthe other inwardly turned end ltd whereof is hooked through acorresponding opening provided in the outer wall of a spring dog i i-i5.It is preferred to anneal or otherwise treat the main spring prior toassembly so as to overcome any otherwise existing tendency of thisspring to take a set after being placed in service.

The dog M6 is of cup-shaped form, the inner whereof open, and the baseits whereof is provided with a non-circular opening, which nonrotatablyreceives the complementarily formed portions t lt of the arbor 32. Theinner surface of the base its bears against shoulders, such as I50,formed on the arbor 32, and the dog t lt is maintained in place on theportions M9 by a nut l52, which is threaded on to the outer reduced endof the arbor 32. The main spring housing 152, in turn, is provided witha plurality of axially extending, circumferentially distributed teeth orprojections which project through corresponding openings provided in thefront movement plate 92. The housing Hi2 may, therefore, be secured tothe movement plate $2 in any one of a plurality of rotative positions,each whereof corresponds to a different initial loading of the mainspring 38.

The just described arrangement, wherein the main spring and its housingare mounted external to the movement plate and are readily connectibleto and disconnectible therefrom, not only permits ready replacement ofthe main spring, but also serves a further important advantage ofenabling the movement, comprising the arbor, the main gear, and theintermediate gears, to be freely run in before the escapement and themain spring are applied.

The setting dial 34 is herein illustrated as being formed of a plasticor other moldable composition, having a generally circular body portionprovided with graduations Ifill, and having a blade-like or otherwiseformed readily graspable central handle portion 162. The inner face ofthe dial 3 3 is provided with diametrically opposite pockets its, whichreceive tongs IE6 provided on a setting lever I63. The lever 163, inturn, is nonrotatably secured to the arbor 32, between the nut I52 andthe dog H56. The dial 34 is also provided with a central recess I70,which receives the nut I52, and preferably, and as illustrated, a usualholding spring H2 surrounds the nut and frictionally engages the innersurface of the pocket fill. If desired, a set screw IN or other meansmay be provided to more positively secure the dial 3 3 in assembledrelation to the arbor 32.

The provision of a circular dial having the graduations distributedtherearound is regarded as an important feature of the presentconstruction. It will be appreciated from Fig. 1 that in the zero orre-set position of the timer, the zero point on the dial 34 registerswith the reference mark Hit or other indication carried by the faceplate V58. To set the timer, the dial 3 1! is rotated clockwise, asviewed in Fig. 1, from the just mentioned initial position, during whichmovement the graduations on the dial successively register with thereference mark I 75 on the face plate. The interval for which the timeris set may thus be initially read at a fixed point on the unit, thusentirely overcoming the confusion which results from the use of dialswherein a movable pointer on the setting member is required to be movedinto registry with fixed numerals distributed around the face plate.

From the description thus far given, it will be appreciated that thejust mentioned clockwise setting movement of the dial 34 positivelyrotates the arbor 32 in a counterclockwise direction as viewed in Fig.5, said rotation being transmitted to the arbor through the drivingconnection afforded by the setting lever I68. The just mentionedrotation of the arbor correspondingly drives the spring dog I46 in acounterclockwise direction, as viewed in Fig. 4, thereby winding up orloading this spring. The rotation of the arbor 32 applies a rotativeforce through the clutch plate 53, which tends to rotate the main gearas in a counterclockwise direction, as viewed in Fig. 5. This tendencyis transmitted through the gear train to the escape wheel 42 and tendsto rotate the latter in a counterclockwise direction, which is theopposite to the direction of rotation normally imparted thereto by themain spring 38. The just mentioned reverse movement of the escape wheel42 brings a tooth into engagement with the back of the tooth I22 on thepallet 44. The radius of the pallet in the region 'at the back of thetooth I22 is too great to allow a movement therepast, in acounterclockwise direction, of the escape wheel. The pallet 44 thereforeoperates to prevent reverse movement of the escape wheel and of the maingear 40. During a setting movement of the dial 34, therefore, the clutchplate 53 slips past the main gear 40. Upon release of the dial 34,however, the main spring 38 becomes eirective to apply a torque to thearbor which rotates the latter in a clockwise direction, as viewed inFig. 5, the rate of such clockwise or return movement being determined,of course, by the escapement, as aforedescribed. The return movement isstopped at the zero position of the timer by the bell hammer mechanismnow to be described, and at the conclusion of such movement also, thebell hammer mechanism operates to give one or more audible signals.

Referring particularly to Figs. 2 and 8 through 14, the hammer mechanismcomprises generally a driving dog I80, 2. setting pawl coil I82, aplurality of hammers I84 and I85, two being shown by way ofillustration, and a tripping lever I87, The dog I80 is illustrated as acup-shaped stamping having a non-circular opening in its base whichco-operates with flats such as I8I on the arbor 32 to provide a drivingconnection for the dog I80. The inner face of the dog I80 engages thetrip lever I81. and movement of the dog I80 along the arbor 32 in theother direction is limited by the overlying portion I89 of thehereinafter mentioned bracket 204. The pawl I82 is of generally bellcrank shape having legs I86 and I88. A pair of ears I90 extend laterallyfrom the leg I88, and are provided with bearing openings through whichthe reduced end portion I92 of the arbor 82 is freely passed. The pawlI82 is normally maintained in seating relation to the dog I80 by meansof a compression spring I96 which surrounds the reduced portion I92 ofthe arbor, and which spring normally causes the dog I80 to engage thelever I81. One end of spring I96 bears against the leg E88 and the otherend thereof bears against the leg I85 of the pawl. The latter end of thespring is straightened, and is received in a notch I98 cut in thereduced portion I92 of the arbor. With this relation, it will beappreciated that any movement of the pawl I82 to the right, as viewed inFig. 2, compresses the spring I86 somewhat, rendering it efiective, uponrelease of the pawl, to restore the latter to the normal position shownin Fig, 2.

A driving lug 209, having a sloping back, is pressed outwardly from thedriving dog I88, and upon rotation of the dog I89 in a counterclockwisedirection, from the off position shown in Fig. 9, toward the on positionshown in Fig. 8, the abrupt face of the lug 200 engages behind the legI88 of the pawl I82, and applies a rotative force to the latter. Thejust mentioned rotation of the pawl I82 brings the hammers I 84 and I85from the tripped positions of Fig. 9 to the cooked positions of Fig. 8,as hereinafter described. Shortly after the pawl reaches a position inwhich the hammers assume the cooked positions, the leg I85 of the pawlencounters a gradually rising cam surface 202 which is struck from thebody of a bracket 204 which is rigidly but adjustably secured to therear movement plate 84. The continued movement of the pawl past the camsurface 202 enables the latter to cam the pawl I82 from the positionshown in Fig. 2 to a position far enough to the right thereof to clearthe lug 208. When the lug 280 clears the pawl I82, the driving force ofthe dog I on the latter is relieved, enabling a continued settingmovement of the dial and of the arbor 32 without further altering theposition of the pawl E82. On the other hand, during the return or timingmovement of the arbor 32, the dog I 80 moves in a clockwise direction,as viewed in Figs. 8 and 9. Due to the fact that the pawl I82frictionally engages the surface of the dog I80, and also has africtional engagement with arbor 32, the return movement of the arbor 32may serve to return the pawl I82 from the setting position shown in Fig.8 to the setting position shown in Fig. 9. If not, the gradual returnmovement of the dog 58:? ultimately brings the grounded back of the lug288 into engagement with the front face of the pawl leg I86, enablingthe dog H353 to rotate the pawl I82 to the normal position of Fig. 9. Alimit to the return movement of the pawl I82 is afforded by a lug 206which is struck outwardly from the previously mentioned bracket 284. Assoon as the pawl I82 engages the lug 286, the further movement there ofis interrupted, and the continued movement of the dog I89 enables thesloping back of the lug 280 to again lift the pawl I82 off its seat,enabling the lug 298 to passbehind the pawl to the normal position shownin Fig. 9.

Except as hereinafter noted, the hammer I84 I85 are duplicates. Thehammer I84 comresses a relatively heavy head 2I0, which is soured at theouter end of a length of relatively heavy spring wire 292, the other endwhereof is igidly secured to a post 2I3 which is secured to and projectsfrom the previously mentioned bracket 294. In the released position ofthe hammer shown in Fig. 9, the wire 2I2 bears, at an intermediatepoint, against one of the previously mentioned pillars 96, which acts tolimit the radial outward movement of the hammer head H9. The head 250 ismade up of two complementary portions Mile and 2I8b which arepermanently secured to each other, as by riveting over the ends of thetongues ZIEic, formed on the member 240a, and which project throughcorresponding openings provided therefor in the body of the member2501). The free end of the wire 2 I2 is rigidly clamped between theportions 2I8a and The head member 2I9b is provided with an extended arm2M, having a finger 2H5 which lies in the path of movement of leg I88 ofthe pawl and also having a hook 2I8. In the cooked position of thehammer, the hook engages the latch 228 which may be and preferably isformed as a flange projecting from the bracket 204. As most clearlyappears in Fig. 10, the flange 228 is provided with a slot 222individual to each hammer. In the cocked position of each hammer, thehook 2E8 thereof engages over the lower end of each slot 222.

It will be appreciated that the tripping of the hammers I84 and 85 fromthe cocked positions of Fig. 8 enables these hammers to give the signalsfor which the device is designed and this tripping action isaccomplished by means of the previously mentioned tripping lever I8'I,which is loosely journalled on the arbor 32 for swinging movement fromthe oiT position shown in Fig. 9 to the on position shown in Fig. 8.

Fhe previously mentioned driving dog [fill is provided with an inwardlystruck lug Zilil, and the just mentioned tripping lever it? is providedwith an outwardly struck lug 2'52 which lies in the path of movement ofthe lug The normal position of the parts is that shown in Fig. 12, inwhich the lug 23E lies immediately in front of, but in engagement with,the lug 232 and in. hich position the nose 23 of the tripping lever it!engages an abutment 236 formed on the previously mentioned bracketflange 22%. The tripping lever liil thus co-operates with the do ii???to form a limit stop to the return or timing movement of the timingdevice, and it will be understood that the dog let drives the lever iiilinto engagement with the abutment 236 when the zero point on the dialregisters with previously ientioned mark H on the face plate llti (Fig.l) A setting movement of the timer, as previously described, causes thearbor to drive the dog Hill in a counterclockwise direction, as viewedin Figs. 8 and 9. This movement causes the lug 23% to move away from thelug 232. The friction between the interengaging marginal. edge portionsof the dog and the lever till enables the dog i331 to frictionally movethe lever it? from the off position of Fig. 9 to the on position of Fig.8. In the latter position, the nose 233 thereof engages an abutment 2%formed on the previously mentioned bracket After, as the just mentionedlimit to the movement of the tripping lever i3? is reached, slippageoccurs between the lever i8! and the dog tell, enabling latter tocontinue in the counterclockwise direction without further altering theposition of the lever If the setting movement of the dial is continuedthroughout the full 360 degrees of movement thereof, the concluding partof such movement brings the lug 23o int-o engagement with the back ofthe lug 2321. Consequently, the tripping lever l8! co-operates with thedog ib not only for the purpose of forming a limit stop to the returnmovement of the timer, but also for the purpose of forming a limit stopto the setting movement thereof.

Assuming that the setting movement of the dog l as influenced by thedial lid, is interrupted either when the just mentioned limit is reachedor is interrupted at an intermediate position, the release of the dialSill enables the main spring so to initiate a return or timing movementof the dog 586. During the course of the just mentioned return movement,the lug 23!! again engages the face of the lug and continued returnmovement of the dog its cams the trip lever i3 from the on position ofFig. 8 towards the on position of Fig. 9. During this movement of thelever E57, the flange 242 formed thereon engages under the noses 244 ofthe hammer arms 2M. This action enables the tripping lever lii'i to camthe noses 2M radially outwardly, as viewed in Fig. 8, and ultimatelyreleases these arms from the latch 22s. Upon being released, the energstored in the springs are associated with the individual hammers whipsthe heads of the hammers radially outwardly. as viewed inFigs. 8 and 9.During the course of this whipping movement, the springs engage thesupporting post 96, as described previously, so that the final whippingmovement occurs as a result of fiuxure of that part of each springbetween the pillar 9t and the associated head. The weight of the heads2lii carries them 14 to the position shown in Fig. 9, enabling them tostrike the bell 2% associated with the timer.

It is sometimes desired to produce two bell notes or two successiveoperations of the hammers H4 at spaced intervals. This result may beaccomplished, as shown in Fig. 10, by making the edge 2% of flange 242of stepped form, or alternatively, if the edge 243 is a straight edge,by providing slightl diiierent tapers on the undersides of the noses 243 of the hammer arms, which portions are engaged by the flange 2% of thetripping lever.

It will be noted from Figs. 2 and 10, that the movement 36 and theprincipal parts of the hammer mechanism are housed within a cup-shapedenclosure 258. The base of the enclosure 25%] is provided with threeopenings, through which the extreme ends of the pillars 96 are passed,and in order to secure the enclosure 259 against axial movement off ofthe pins, a conventional clip spring 252 is preferably employed, thebody whereof hooks beneath grooves formed in the pin extremities, aswill be understood. The side of the enclosure 254] is provided with anopening 254, through which the heads of the hammers I34 and it? mayproject upon being tripped by the tripping level Ial, and in the presentinstance, the bell 2%, which is also of generally cup shape. is secureddirectly to the back of the enclosure 2% by means of a countersunk screw25%.

A feature of the present arrangement resides in an improved method formounting and adjusting the hammers, it being appreciated that in orderto ensure a clear, unblurred note from each hammer, the normal spacingbetween each hammerhead and the inner surface of the bell should be heldbetween rather close limits. In view of the fact that each hammer iscarried by a section of spring wire, and further in View of the factthat the characteristics of this wire vary somewhat, the presentinvention provides for the use of a fixture having pillars correspondingto the pillars and 95, against which each spring 2l2 bears, viewed inFigs. 8 and 9, together with means for supporting the head elements Zitaand Zillb in proper position. Thus, the free end of the spring 2 l 2 maybe allowed to take up a free radial position between the head elements 2i (la and 2 l 0b, after which the elements 2963a and illilb may berigidly secured together with the spring 2l2 clamped therebetween.

It will be recalled from the previous description hat the abutment 2% onthe hammer bracket co operates with the trippin lever It! to form alimit to the setting movement of the timer, and that the abutment 2%carried by the bracket 2% co-operates with the lever i8l to form a limitto the return or timing movement of the timer. Accordingly, in order toallow for initial adjustment of the timer, so as to insur that the zeropoint on the dial 341 will arcuately register with the mark Ht on theface plate H8 in the reset position. of the timer, the bracket 2% isrotatably adjustable relative to the movement plate 92. For thispurpose, the bracket 2M- is secured to the movement plate 92 by means ofthree circumferentially distributed screws 269, each whereof may bethreaded into a tapped opening in the movement plate 9 5, and eachwhereof passes through elongated slot formed in the bracket 2%. Asillustrated, fine adjustments of the bracket 264 facilitated byproviding the latter with a series of gear-like teeth 262, which aredisposed for meshing engagement with corresponding teeth on a tool (notshown) which may be introduced into a drilled opening 2% in the mountingplate 92 and 15' rotated so as to correspondingly rotate the bracket284.

It will be noted from the previous description that the entire timeassembly is directly supported by the movement plates 92 and 94-. Inorder to secure the timer to the face plate I18, it is preferred toprovide the latter with a plurality of inwardly struck lugs 25L whichpass through corresponding slots formed in the movement plate 82 andwhich lugs may be slightly twisted by a pair of pliers or similar toolso as to lock the parts in assembled relation to each other. Thetwisting of the lugs draws the inner marginal edge of the enclosure 250into engagement with the inner face of the face plate I78. The faceplate I18 may, of course, be secured to any suitable casing or box inany desired manner. The just mentioned twistable lugs are found inpractice to admit of frequent removals of the movement from the faceplate without impairing the efficiency of the connection, or withoutcausing the lugs to break off.

The present escape mechanism is found in practice to operate relativelyquietly. In certain instances, however, it is found preferable toutilize the somewhat resilient escape wheel construction, shown in Figs.20 and 21. In these figures the escape wheel 219 is formed of a singlesheet of metal, such, for example, as spring bronze. The center bodyportion is planar and is provided with an opening 2'E2 to receive thesupporting arbor or stafi. The successive teeth of the escape wheel 278are constituted by fiat ends 214 and spokes 2'53. It will be noticedthat the ends 214 are substantially co-planar with the center bodyportion of the wheel, but that the spokes 216 are twisted relative tothe ends and the body through approximately 90 degrees, so that suchspokes relatively readily flex slightly when they engage the associatedpallet, such as 44. This flexing softens each impact between the escapewheel and the pallet and consequently makes the operation of theescapement wheel exceedingly quiet.

Considering now the operation of the timer as a Whole, it will beappreciated that th parts are shown in Figures 1 and 9 in the normal, oroff, position thereof, in which the zero point on the dial 34 registerswith the mark I16 on the face plate I18 and in which the hammers I84 andI85 occupy their released positions. In these latter positions thesprings associated therewith bear against the associated movement pillar9B, and are thereby maintained out of contact with the bell 2&6. Underthes conditions, also, the main spring is subjected to a normal loadingdetermined, as previously described, by rotating the spring housing I l2relative to the arbor as an incident to the assembling of the mainspring with the movement The main spring thus urges the arbor 32 in aclockwise direction, as viewed in Figure 9, tending to move th dial in acounterclockwise direction (Figure l) past the zero point. Such movementis, however, prevented by the engagement of the nose 23 of the trippinglever I8? with the abutment 236 on the adjusting bracket 28%. Until setby the dial 34, therefore, the timer remains at rest at the justmentioned zero position.

Assuming it is desired to effect an operation of the timer, the dial 34may be rotated in a clockwise direction, as viewed in Figure 1,throughout all or part of the permitted 360 of movement thereof. Thearbor 82 moves directly with the dial during this setting movement. Theinitial arbor movement drives the movement 36 in an opposite directionuntil such a time as a tooth of the escape Wheel 42 binds against theback of the pallet tooth I22, thereby blocking further such reversemovement. Following this blocking action, the continued movement of tharbor 32 causes slippage of the clutch plate 58 past the main timer gear48. The setting rotation of the arbor 32 also winds up the main spring38, as previously described.

The setting rotation of the arbor 32 causes a corresponding rotation ofthe dog I89 associated with the hammer mechanism. The initial suchrotation of the dog I80 rocks the pawl I82 in a counterclockwisedirection, as viewed in Figure 9, enabling the leg I88 thereof, throughits engagement with the fingers 2I6 of the hammer arms 2I4, to move thehammers from the off, or tripped, position of Figure 9 to the cockedpositions of Figure 8, at the conclusion of which movements the hammerarms snap behind latching bracket 220. Shortly after the just mentionedlatching of the hammers is effected, the arm I88 of the pawl I82 ridesup on the lug 202 and is thereby cammed to the right, as viewed inFigure 2, far enough to clear the driving lug 208 on the dog I80. Itwill be appreciated that th setting movement may be stopped at any timeafter the cooking of the hammers is effected, which cocking may bearranged to take place in the course of a relatively few degrees ofrotation of the dial 34.

Due to the frictional connection between the dog I88 and the trippinglever I87, the initial rotation of the dog I88 moves the tripping leverfrom the on position of Figure 9 to the on position of Figure 8, inreadiness to provide a limit stop to the setting movement of the dial34. This movement of the tripping lever I8! also carries the flange 242thereof out of co-operative relation to the noses 228 of the hammer armsso that the tripping lever I81 does not interfere with the cocking ofthese hammers.

If the setting movement is continued throughout the full 360 ofpermitted movement thereof, the final such movement thereof brings thelug 238 on the dog I into engagement with the back of the lug 232 on thetripping lever I81, thereby tending to rotate the latter in acounterclockwise direction beyond the position shown in Figure 8. Anysuch further movement is, however, prevented by the engagement of thenose 238 of the tripping lever with the abutment 240 on the adjustablebracket 284. The lever I81, therefore, prevents movement of the dial 34beyond the full 360 of movement.

Assuming the dial 34 is released at any point between the point at whichthe hammers are cooked and the just mentioned limit position, the mainspring 38 is immediately rendered effective to drive the arbor 32 in aclockwise direction (Figures 5, 8 and 9) at a rate determined by theescapement which controls the return movement of the arbor 32 throughthe clutch connection between the clutch plate 58 and the main gear 48.During the course of such return movement of the arbor 32, the dog I88may be expected to frictionally drive the pawl I82 back to the positionof Figure 9. If the frictional force is not sufficient to do this, thecontinued movement of the dog I88 brings the lug 288 into engagementwith the back of the pawl arm I86, enabling the latter to positivelyreturn the pawl. When the pawl reaches the normal position shown inFigure 9, the arm I88 thereof engages the fixed lug 286, enabling thelug 200 to cam the pawl I82 to the right, as viewed in Figure 2, farenough to permit the lug 200 to pass behind the pawl and resume theposition shown in Figure 9. As the dog I80 approaches the zero, orstarting, position, the lug 230 on the dog I80 comes into engagementwith the lug 232 on the tripping lever I81. Continued return movement ofthe dog I80 swings the tripping lever I87 from the on posi tion ofFigure 8 toward the off position of Figure 9. In the course of thismovement, the flange 242 on the tripping lever I81 successively engagesthe noses 220 on the hammer arms 2I4 and cams these arms out of engagingrelation to the latch 220. As each hammer arm is released from thelatch, the energy stored in the spring 2I2 associated therewith whipsthe head of the hammer into engagement with the bell 246, as describedabove. It will be understood that the interval between each bell note isdetermined by the configuration or proportioning of the noses 244 of thearms 2I4, it being preferred, of course, that the final bell note betimed to occur substantially simultaneously with the arrival of the dialat the zero position. When the dial arrives at the zero position, also,the nose 234 of the tripping lever l81 engages the abutment 236 on thebracket 204, thereby stopping the return, or timing, movement.

As described above, the escape rate of the present mechanism can bevaried over a substantial range by adjusting the tension of the spring48 and by changing the number of teeth on the escape wheel 42. For eachescape rate, also, the time required for a full 360 of travel of thedial depends upon the gear ratio employed. Certain changes in the gearratio can best be made by the addition to or elimination from the gearset of one or more gears. In certain instances it is, therefore,desirable to arrange the escape mechanism to accommodate rotation of theescape wheel 42 in either direction. Such an arrangement is shown inFigs. 24, 25 and 26, in which the pallet 44 is provided with a singleradially projecting finger I22, the respectively opposite radial faceswhereof correspond to the previously described shoulder I22. Inaddition, the pallet 44 is provided with two shoulders I24 and I24,which individually correspond to the shoulder I24 and which aresymmetrically arranged at either side of the finger I22. The rotativeposition of the spring bracket I20 with respect to the pallet 44 and themounting for the fixed end of the spring I48 are such that the spring 48always tends to rock the finger I22 to a position in which it liesbetween and on a line with the axis of the pallet shaft 90 and the axisof the escape wheel 42.

As will be appreciated, Figs. 24 and 26 correspond, respectively, toFigs. 16 and 18, and the operation of the escapement, consideringclockwise rotation of the escape wheel 42, is the same as previouslydescribed with reference to Figs. 16 and 18. If, however, the gearing ischanged so as to produce counterclockwise rotation of the escape wheel42,, the parts cooperate as shown in Fig. 25. That is to say, the toothof the escape wheel bears against the righthand radial face of thefinger I22 and urges the pallet 44 in a clockwise direction sufficientlyfar to bring the shoulder I24" into blocking relation to the nextsucceeding escape wheel tooth. The spring 48 opposes the just-mentionedrotation of the pallet 44 and swings the same in a counterclockwisedirection, thereby releasing such next succeeding escape wheel toothfrom the shoulder I24 and 18 allowing such tooth to advance and strikethe finger I22 as just described. In other respects, the operationdepicted in Fig. 25 is the same as previously described.

In Figures 27 and 28 is illustrated a further modification of theescapement, in which the escapement element, or pallet, is formedintegrally with the balance staff and a slightly modi fied form ofresilient escapement wheel is provided. As shown best in Figures 27 and28, the balance staff is illustrated on a larger scale than in Figures24 to 26. The balance staff 90', however, except for the details of theescapement element itself, hereinafter described, is similar inarrangement and construction to the balance stafi 90, previouslydescribed and illustrated. In this form of the invention, the escapementelement or pallet 280 is similar in form to the element 44', illustratedin Figures 24 and 26, being provided with a pair of shoulders 28Iforming braking surfaces, a pair of escape notches 282, and anintermediate radial projection 283 which extends radially to asubstantially greater degree than the shoulders 28I and which receivesthe impulse from the escapement wheel. The escapement element 280,including the escapement notches and the radial projection 283, isformed integral with and from the balance stafl 90 by a stampingoperation, in the manner illustrated in Figure 29. As shown in Figure29, the balance staff 90 is placed between a pair of die elements 290and 29I which, when forced together, form the notches 282 in the balancestaff and extrude the metal which formerly occupied the notched spacesto form the radial projection or impulse member 283.

It will be observed that in the escapement element of Figures 27 and 28,as well as the escape ment element of Figure 24, the corner between thebraking surface and the notch is rounded in the manner illustrated anddescribed in connection with the pallet 44, illustrated in Figures 16and 17, except that the notches and braking surfaces are duplicated inthe reversible form of pallet.

The form of escapement element or pallet illustrated in Figures 27 and28 may be used equally well with an escapement wheel of the formillustrated in Figures 24 to 26 or of the form illustrated in Figures 20and 21. However, there is illustrated in Figure 27 a further modifiedform of escapement wheel 292 provided with a plurality of resilientteeth 293. The escapement wheel 29I is formed of sheet metal and has aflat central portion 294 secured in any suitable man ner to a hub 295,which is provided with pinion teeth 298 adapted to mesh with the teethof gear I8 in the manner illustrated in Figure 7. The teeth 293 areformed integrally from the same sheet of metal as the central portion294, and are initially 0f the width indicated in dotted lines at 291.However, after the Wheel is blanked out of the sheet metal, the teethare twisted through an angle of 90 at the point 298 adjacent the basesso that the plane of the teeth extends parallel to or contains the axisof the wheel. This produces a relatively thin, fiat-bladed resilienttooth for cooperation with the escapement element 280 in the mannerdescribed in connection with the resilient escapement wheel illustratedin Figures 20 and 21.

It will be understood that the form of escapement wheel illustrated inFigure 27 may be substituted for the escapement wheel 42 in Figures 1916 and 1'7 or for the escapement wheelAZin Figures 24' to26, if desired;

While several specific embodiments of the invention have been describedin detail, it' will be appreciated that Various modifications in theform, number and arrangement of parts may be made without departing fromthe spirit and scope of the invention.

What is claimed is:

1. An escapement mechanism comprising an oscillating balance staff,means directly on and movablewith said staff forming an escapement spacepermitting escapement of teeth successive- 1y; said means also having abraking surface associated therewith, and an escapement Wheel havingperipherally arranged resilient teeth cooperating with said meansmounted on the staff for escapement through said space, and cooperablewith said braking surface prior to passage through said space.

2. An escapement mechanism comprising an oscillating staff, anescapement member mounted on and movable with the staff, said memberhaving an'extension therefrom and a braking surface thereon with spacetherebetween, and an escapement wheel having peripherally arrangedresilient teeth cooperating -resiliently with the braking surface of theescapement'member and passing through said space'into resilientcooperation with said extension for driving the latter.

3. An escapement wheel comprising peripherally arranged teeth, each ofwhich consists'of a plane of springy material arranged as a cantilever,-said plane havin'g'an outer edge of substantial length which issubstantially parallel to the axis of the wheel.

4. An escapement mechanism comprising an oscillating balance staff,'means on said staff forming an escapement space permitting escapemeritof teeth successively, said escapement means also having anextension'and a braking surface associated therewith, and an escapementwheel having peripherally arranged resilient teeth cooperatingresiliently with the braking surface of the resilient member and passingthrough said space and cooperating with said extension for driving thelatter, the plane of resilient movement of said teeth being paralleltothe plane of movement of saidextension,

5. An escapement mechanism comprising a rotatable escapement wheelhaving a plurality of peripherally arranged teeth, an oscillatingbalance staff, and escapement means directly on and movable with saidstaff for permitting escapement of said teeth progressively, said meanshaving a braking surface for successively engaging said teeth and asubstantially radially projecting impulse surface adapted to be struckby each tooth as 'it is released from said braking surface, said brakingsurface and impulse surface being separated by a notch of sufficientsizelto permit pas'sag'eof one to'oth of said wheel at a time, saidbraking surface being a curved surface whose radius from the axis ofsaid'means progressively decreases as the surface approaches said notch.

6. An escapement mechanism comprising a rotatable escapementwheel'having a plurality of peripherally arranged teeth, an oscillatingbalance staff, and escapement means directly on and movable with saidstaff for permitting escapement of said teeth progressively, said meanshaving a braking surface for successively engaging said teeth and asubstantially radially projecting impulse surface adapted to be struckby each tooth as it is released from said braking surface,

said braking surface and'impulse surface being separated by a notchofsufficient size to permit passage of one'tooth of said wheelat a time,said braking surface being a curved surface whose radius from the axisof said means progressively decreases as the surface approaches'saidnotch beginning with a curve approximately concentric to the axisof oscillation of saidmeans and terminating at said notch in a curvewhose tangent is approximately perpendicular to the plane of saidimpulse surface.

7. An escapement mechanism comprising a-rotatable escapementWh'eelhaving a plurality of peripherally arranged teeth, an'oscillatingbalance staff, and escapement means directly on and movable with saidstaff .for permitting escapement of said teeth progressively, said meanshaving a braking surface for successively engaging said teeth and asubstantially radially projecting impulse surface adapted to be struckby each tooth as it is released from said'braking surface, said brakingsurface and impulse surface being separated by a notch of sufficientsize to permit passage of one tooth of said wheel at a time, saidbraking surface being a curved surface whose radius from the axis ofsaid means progressively decreases as the surface approaches'said notchand said impulse surface projecting from said axis of oscillation asubstantiallygreater distance than'any part of said braking surface.

3. An escapement mechanism comprising arotatable escapement wheel havinga plurality of peripherally arranged teeth," an oscillating bal-t ancestaff, and escapement means directly on and movable with said staff forpermitting'es capement' of said teeth progressively, said means having abraking surfacefor successively engag-j ing' said teeth andasub'stantially radially pro- -je'cting impulse surface adapted'to bestruck by each to'oth' as it is 'reIeased'fr'om said brakingsurfacepsaid braking surface andimpulse surface being'separa'ted by anotch of sufficient size to permit passage of one tooth of said wheel ata time said braking surface being a curyed sure face whoseradius-fromthe axis of said means progressively decreases as the surfaceapproaches said notchbeginning witha curve approximately concentrictothe axis of oscillation of said means and terminating at said notchjin acurve whose tangent is approximatelyperpendicular to the plane ofsaidimpulse surface and said impulse surface projecting from saidaxis ofoscillation a substantially greater said braking surface.

9. A reversible escapement mechanism com-, prising a rotatableescapement wheel having a plurality of peripherally arranged radiallypro- J'ec'tin'g teeth, an oscillating balance staff :lhaving' a radialprojection defining a pair of oppositely; directed substantiallyradially-extending impulse surfaces, one impulse surface beingadapted'tobe engaged successively by said teeth whensaid Wheel is rotating in onedirection and the'other e di b nga e sucq lyrbr a e h when said wheel isrotating in the other direction, said element havin a notch formedtherein at each side of said projection, one notch being adapted topermit p'assage of oneofsaid teeth at a time into contact with saidprojection when the'wheel rotates in one direction and theother notchbeing adapted, to permitsuch passage of one of said teeth at a time intocontact with'said projection when the Wheel rotates in the 'oppositedistance than part :or

direction, and said element having at the opposite sides of each notchfrom said projection a braking surface adapted when the element is inone rotative position to engage one of said teeth and interrupt themovement of said tooth toward the projection and adapted to permitmovement of said tooth through the notch and into engagement with saidprojection when the element is in another rotative position, one of saidbraking surfaces being operative when the wheel is rotating in onedirection and'the other braking surface being operative when the wheelis rotating in the opposite direction, and a spring eccentricallyconnected to said balance staff and having a dead center position whensaid projection extends toward the axis of said wheel.

10. A reversible escapement mechanism comprising a rotatable escapementwheel having a plurality of peripherally arranged radially projectingteeth, an oscillating balance staff having an escapement element fixedto said balance staff and having an integral radial projection defininga pair of'oppositely directed substantially radially extending impulsesurfaces, one impulse surface being adapted to be engaged successivelyby said teeth when said wheel is rotating in one direction and the otheradapted to be engaged successively by said teeth when said wheel isrotating in the other direction, said balance staff having a notchformed directly therein at each side of said projection, one notch beingadapted to permit passage of one of said teeth at a time into contactwith said projection When the Wheel rotates in one direction and theother notch being adapted to permit such passage of one of said teeth ata time into contact with said projection when the wheel rotates in theopposite direction, and said balance staff having at the opposite sidesof each notch from said projection a braking surface adapted when thebalance staff is in one rotative position to engage one of said teethand interrupt the movement of said tooth toward the projection andadapted to permit movement of said tooth through the notch and intoengagement with said projection when the balance staff is in anotherrotative position, one of said braking surfaces being operative when thewheel is rotating in one direction and the other braking surface beingoperative when the wheel is rotating in the opposite direction, and aspring eccentrically connected to said balance staff and having a deadcenter position when said projection extends toward the axis of saidwheel,

11. A unitary balance staff and escapement element comprising agenerally cylindrical shaft having a radial projection formed integrallytherewith, said shaft having notches at each side of the projectionadapted to act as escapement spaces.

12. An escapement mechanism comprising an oscillating balance staff, ashaft extending parallel to said staff, an escapement wheel on saidshaftesaid wheel having a central sheet metal web portion and resilientperipheral teeth projecting substantially radially from said web portionand integral with said Web portion, means directly on and movable withsaid staff defining a peripheral braking surface adapted in one rotativeposition of said stafi to engage the extremity of one of said teeth andblock movement of said wheel, said means defining the braking surfacebeing adapted on rotation of said staff in one direction from saidposition to release said tooth and permit rotation of said wheel, aspring acting to rotate said staff in said one direction when saidbraking surface is in engagement with a tooth of said wheel, and meansdirectly on and movable with said staff forming a substantially radiallyprojecting impulse surface in a position to be engaged by the extremityof each tooth of said Wheel when the tooth is released from said brakingsurface and to be moved by the tooth in a direction to rotate said staffin the opposite direction into the position in which said brakingsurface engages the next succeeding tooth of said wheel.

13. An escapement mechanism comprising an oscillating balance staff, ashaft extending parallel to said staff, an escapement wheel on saidshaft, said wheel having a central sheet metal web portion and resilientperipheral teeth projecting substantially radially from said web portionand integral with said web portion, means directly on and movable withsaid staif defining a peripheral braking surface adapted in one rotativeposition of said stafi to engage the extremity of one of said teeth andblock movement of said wheel, said means defining the braking surfacebeing adapted on rotation of said staif in one direction from saidposition to release said tooth and permit rotation of said wheel, saidperipheral braking surface terminating adjacent the releasing extremitythereof in a peripheral braking surface of progressively decreasingradius from the axis of said staff to effect a gradual release of saidtooth as said staff rotates in said one direction, a spring acting torotate said staff in said one direction when said braking surface is inengagement with a tooth of said wheel, and means directly on and movablewith said staff forming a substantially radially projecting impulsesurface in a position to be engaged by the extremity of each tooth ofsaid wheel when the tooth is released from said braking surface and tobe moved by the tooth in a direction to rotate said staff in theopposite direction into the position in which said braking surfaceengages the next succeeding tooth of said wheel.

14. An escapement mechanism comprising a rotatable escapement wheelhaving a plurality of peripherally arranged teeth, an oscillatingbalance staff, and escapement means directly on and movable with saidstaff for permitting escapement of said teeth progressively, said meanshaving a peripheral braking surface for successively engaging said teethand a substantially radially projecting impulse surface adapted to bestruck by each tooth as it is released from said braking surface, saidbraking surface and impulse surface being separated by a notch ofsufficient size to permit passage of one tooth of said wheel at a time,said braking surface being a curved surface having a portion adjacentsaid notch whose radius from the axis of said means progressivelydecreases as the surface approaches said notch beginning with a curveapproximately concentric to the axis of oscillation of said means andterminating at said notch in a curve whose tangent is approximatelyperpendicular to the plane of said impulse surface,

15. An escapement mechanism comprising an oscillating balance staff, ashaft extending parallel to said staff, an escapement wheel on saidshaft and having peripheral teeth extending substantially radiallytherefrom, means directly on and movable with said staff defining aperipheral braking surface adapted in one rotative position of said.staff to engage the extremity of one of mit rotation of said wheel,saidperlpheral bra-k- 5 ing surface. terminating adjacent the releasingextremity thereofin a peripheral braking surface of progressivelydecreasing radius from, the axis of said stafi to permitagradualreleaseof said tooth as said staff rotates in said one direc tion, a springacting to rotate said stafi in said one direction when said brakingsurfaceis in engagement with a tooth of said wheel, and means directlyon and movable with said staff forming a substantiallyradially,pnpjecting impulse surface extending radiallyto a reaterextentthan the maximum radius of said; braking surface and adapted to beengaged by'ea ohtoothof said wheel when the tooth is releasedfromsaidbraking surface and to be moved by the tooth in a direction torotate said staff inthe opposite directionto shift said stafi" into theposition in which said braking surface-engages the-next succeeding toothof said wheel.

CHARLES E. GODLEY.

REFERENCES CITED.

The. following references are of record in the file-of this patent:

UNITED STATES PATEN TS Number A- Name Date.

1,934,611 Franz Nov. 7, 1933 1,4u1'L58Z- Calvert Mar. .6, 1923 328,308Hart Oct. 13, 1885 2,150,633: Rhodes et a1 Mar. 14, 1939 1,398,776.Greenwald Nov, 29; 1921 797,730 .Gundorph Aug. 22, 1905 1,861,947Kohler- July.19, 1932 1,895,398: Rhodes Jan. 24, 1933 1,995,363 RhodesMar. 26,1935

FOREIGN PATENTS Number Country Date 27,413- Denmark Apr.;18,' 1921OTHER- REFERENCES Horological Review Publication of Oct. i 1916, pages129 and. 131.

Scientific American Supplement of June. 10, 1905, pages 24,616 and24,617.

